Weighed the DBs at the gym: they are 3-5 lbs heavier than what they say.
Also, worse grip (thinner, non-knurled plastic vs. 1.18" knurled metal).
Mistery solved. But dayhum, they should really write the real weights on the DBs.
My lifts are always lower when I use a new gym. Just being comfortable with the place has a lot to do with performance.